Question

Why does promoter efficiency tend to decrease with the number of G ∙ C base pairs in the -10 region of a prokaryotic gene?

Short answer

During transcription initiation, the promoter with the most G.C pairs does not readily form the open complex, which causes a decrease in promoter efficiency.

Step-by-step solution

Define RNA processing

In molecular biology, RNA splicing is the process by which a newly synthesized precursor messenger RNA (pre-mRNA) transcript is turned into a mature messenger RNA (mRNA).It operates by splicing exons back together after eliminating all introns (RNA non-coding regions) (coding regions).

Decrease of the promoters

The efficacy of the promoter diminishes as the number of G.C (Guanine and Cytosine) base pairs increases. G.C (Guanine and Cytosine) base pairs are more stable than A.T (Adenine and Thymine) base pairs andcreates a stronger stacking connection.. So, the promoter with more G.C pairs has a harder time forming the open complex during transcription initiation. As a result, the effectiveness of promoters in bacterial genes diminishes as the number of G.C base pairs increases.

RNAP will create a closed complex as it binds to the G-C regions. It makes it easier to slow down or even interrupt the sequence's transcription.